Conventional internal combustion engines usually employ pistons, connecting rods, heads, crankshafts, valve trains etc. These engines produce a good deal of vibration, wear and energy loss. To reduce such undesirable faults, various types of rotary engines have been proposed. These rotary engines use rotors having radial vanes cooperating with inside surfaces of cylindrical chambers or stators which are eccentrically mounted. Typical examples of such previously proposed rotary engines are shown in U.S. Pat. No. 1,757,484 to G. Shoemaker and U.S. Pat. No. 4,572,121 to Victor Chang. Both of these patents are concerned with radial motors having side by side rotors which have a valve arrangement to allow compressed air-fuel mixtures to flow from an intake compression stage to an combustion-exhaust stage. Both of these designs fire the explosive mixture at the same place on the stator, one firing per vane per revolution. This style of firing tends to give a side load to the bearings causing wear and subsequently requiring higher oil pressure and oil flow.
Shoemaker shows exposed air passages which cool the air-fuel mixture between compression and ignition. Chang's device has an exhaust problem requiring a third stage to blow the spent gasses from the engine. Also both types of engines have no means of cooling the rotor. Both engines use eccentrically mounted rotors. They can only be fired in one position in the stator. There is a need for improvement with respect to these and other shortcomings to simplify construction and operation. This invention has air flowing down the center to cool the rotors. The rotors are concentrically mounted in a lobated interior of the stator this allows all chambers to be fired simultaneously with multiple firings per revolution.